The chain is currently testing the mobile app in Southern California, Jennings reports.

The app allows customers to customize their taco orders.

Jeff Jenkins, Taco Bell's lead mobile executive, said the restaurant industry is in the process of fundamentally changing how people order.

“Mobile is the biggest shift in QSR since the drive thru,” said Jenkins.

McDonald's is also in the process of testing a mobile ordering app. Starbucks is also laying the groundwork. Chipotle already offers mobile ordering, but is aggressively investing in updates to its platform.